Large-aperture industrial visual inspection lens applied to self-closed loop of vehicle lamp

Abstract

The invention discloses a large-aperture industrial visual inspection lens applied to a self-closed loop of a vehicle lamp. The large-aperture industrial visual inspection lens comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens which are sequentially arranged from an object side to an image side along an optical axis direction, wherein the first lens, the third lens and the fourth lens respectively have positive focal power; the second lens and the fifth lens respectively have negative focal power. By implementing the lens of the invention, the aperture size can be increased to enhance the light collection capability, the lens size can be optimized, and the temperature adaptability can be improved.

Description

Technical Field

[0001] The present invention relates to the field of industrial vision technology, and in particular to a large aperture industrial vision detection lens applied to a self-closing loop of a vehicle lamp. Background Art

[0002] With the development of intelligent technology, car lights, as the "eyes at night" of cars, have shifted from traditional single lighting to intelligent projection interaction and other functions, and have also put forward higher requirements for automated production and testing. Industrial visual inspection based on the self-closed loop of car lights is one of the important processes in the automated manufacturing of car lights. It relies on computer vision technology to realize the detection, identification, measurement and positioning of products during the production process. Among them, the imaging lens, as one of the key components of the visual system, plays the role of accurately transmitting the optical image information of the target object to the image sensor, thereby providing a basis for the intelligent recognition of subsequent algorithms. Selecting an appropriate imaging lens is crucial to ensure high-quality image acquisition.

[0003] Traditional five-element industrial vision lenses have a small aperture, usually with an aperture value of F2.2 to F2.8, which means that they have limited ability to collect light in low-light conditions, resulting in insufficient image brightness. Traditional five-element industrial vision lenses are large in size, which does not meet the requirements of modern compact design, limiting their application in space-constrained environments. When working in different temperature environments, their performance is not stable enough, affecting image quality.

[0004] Therefore, it is necessary to design a new lens to increase the aperture size to enhance the light collection ability, optimize the lens size, and improve temperature adaptability. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects of the prior art and provide a large aperture industrial vision inspection lens for a self-closing loop of a vehicle lamp.

[0006] In order to solve the above technical problems, the purpose of the present invention is achieved through the following technical solutions: providing a large aperture industrial vision inspection lens applied to the self-closing loop of a car lamp, comprising: a first lens, a second lens, a third lens, a fourth lens, and a fifth lens arranged in sequence from the object side to the image side along the optical axis; wherein the first lens, the third lens, and the fourth lens respectively have positive optical focal lengths; and the second lens and the fifth lens respectively have negative optical focal lengths.

[0007] A further technical solution is as follows: a system aperture is arranged between the second lens and the third lens; and a vignetting aperture is arranged on a surface of the second lens close to the first lens.

[0008] A further technical solution is as follows: the first lens comprises a convex lens with positive focal power, the material of the first lens is crown glass, the refractive index of the first lens is between 1.6 and 1.8, and the Abbe number of the first lens is between 40 and 60.

[0009] A further technical solution is: the second lens comprises a concave lens with negative optical power, the material of the second lens is heavy flint glass, the refractive index of the second lens is greater than 1.7, and the Abbe number of the second lens is greater than 20.

[0010] A further technical solution is as follows: the third lens comprises a convex lens with positive focal power, the material of the third lens is crown glass, the refractive index of the third lens is between 1.2 and 1.7, and the Abbe number of the third lens is greater than 40.

[0011] A further technical solution is as follows: the fourth lens comprises a convex lens with positive optical power, the material of the fourth lens is crown glass, the refractive index of the fourth lens is between 1.5 and 1.7, and the Abbe number of the fourth lens is between 40 and 60.

[0012] A further technical solution is: the fifth lens comprises a concave lens with negative optical power, the material of the fifth lens is heavy flint glass, the refractive index of the fifth lens is between 1.6 and 1.8, and the Abbe number of the fifth lens is between 20 and 40.

[0013] A further technical solution is: the optical interval between the first lens and the second lens is 0.5 mm, and the optical interval between the second lens and the third lens is 3.1 mm.

[0014] A further technical solution is: the optical interval between the third lens and the fourth lens is 0.8 mm, and the optical interval between the fourth lens and the fifth lens is 1.6 mm.

[0015] A further technical solution is: the optical interval between the fifth lens and the image plane is 1.6 mm.

[0016] Compared with the prior art, the present invention has the following beneficial effects: the present invention designs a large aperture combination in a lens system, adopts the first, third and fourth lenses as positive power lenses, and the second and fifth lenses as negative power lenses, so as to realize effective light collection and focusing, thereby increasing the aperture size; the configuration of the positive and negative power lenses optimizes the propagation path of the light, so that the system can reduce the size of the optical structure while ensuring the optical performance, thereby achieving a compact design; reasonable lens material and optical spacing design enable the lens to maintain stable optical performance at different ambient temperatures; and finally achieves a higher light collection capability, a smaller lens size and good temperature adaptability.

[0017] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0019] Figure 1 A schematic structural diagram of a large aperture industrial visual inspection lens applied to a self-closing loop of a vehicle lamp provided in an embodiment of the present invention;

[0020] Figure 2 A point diagram of a large aperture industrial visual inspection lens applied to a self-closing loop of a vehicle lamp provided by an embodiment of the present invention;

[0021] Figure 3 A light fan diagram provided by an embodiment of the present invention;

[0022] Figure 4 Field curvature and distortion diagram provided by an embodiment of the present invention;

[0023] Figure 5 A vertical axis chromatic aberration diagram provided by an embodiment of the present invention;

[0024] Figure 6 A diagram of a 25° ambient light transfer function provided by an embodiment of the present invention;

[0025] Figure 7 An 85° ambient light transfer function diagram provided by an embodiment of the present invention;

[0026] Figure 8 A diagram of a 105° ambient light transfer function provided by an embodiment of the present invention;

[0027] Description of the symbols in the figure:

[0028] 1. First lens; 2. Second lens; 3. Third lens; 4. Fourth lens; 5. Fifth lens; S5. System aperture; S12. Imaging surface. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0031] It should also be understood that the terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0032] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0033] Industrial vision relies on computer vision technology for automated inspection, among which the imaging lens is a key component responsible for accurately transmitting the optical image to the image sensor. Choosing the right lens is crucial to obtaining high-quality images. The traditional five-element lens has a small aperture and limited ability to collect light in low-light conditions, which affects the brightness of the image. The five-element lens is large in size and cannot meet the requirements of modern compact designs, limiting its application in space-constrained environments. Its unstable performance under different temperature conditions also affects the image quality.

[0034] To this end, an embodiment of the present invention provides a large aperture industrial vision inspection lens applied to a self-closing loop of a vehicle lamp, which increases the aperture size to enhance the light collection capability, optimizes the lens size, and improves temperature adaptability.

[0035] Specifically, the lens optimizes the optical performance of the lens by designing an optical system with a combination of multiple lenses, especially the design of a large aperture, which significantly improves the imaging brightness in a low-light environment and solves the problem of insufficient brightness of a traditional lens. A combination of a first lens 1, a third lens 3, and a fourth lens 4 with positive focal power, and a second lens 2 and a fifth lens 5 with negative focal power is adopted to improve the imaging quality and ensure that the lens can provide a higher brightness in a low-light environment. By setting an aperture between the second lens 2 and the third lens 3, and setting a vignetting aperture on the side of the second lens 2 close to the first lens 1, the brightness distribution of the imaging is effectively controlled, and the imaging effect in a low-light environment is improved. The precise selection of the material and refractive index of each lens (such as crown glass and heavy flint glass) optimizes the optical transmission characteristics and ensures the imaging quality and brightness when the aperture is large. The design of the lens makes the optical spacing reasonable, reduces the light loss of the traditional lens under low illumination, and effectively improves the utilization rate of light. Under the premise of maintaining a small optical size, the problem of the large volume of the traditional lens is solved through precise optical design, making the lens more compact and suitable for industrial vision applications.

[0036] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0037] See also Figure 1 A large aperture industrial vision inspection lens applied to a self-closing loop of a vehicle lamp comprises: a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, and a fifth lens 5 which are arranged in sequence from the object side to the image side along the optical axis; wherein the first lens 1, the third lens 3, and the fourth lens 4 respectively have positive optical power; and the second lens 2 and the fifth lens 5 respectively have negative optical power.

[0038] In one embodiment, see Figure 1 A system aperture S5 is arranged between the second lens 2 and the third lens 3 ; a vignetting aperture is arranged on a surface of the second lens 2 close to the first lens 1 .

[0039] Specifically, the system aperture S5 is set between the second lens 2 and the third lens 3 (S5 surface) to control the amount of light entering the system; at the same time, a vignetting aperture (S3 surface) is set on the side of the second lens 2 close to the first lens 1 to effectively control the aberration of the off-axis field of view and ensure the imaging quality of the edge area. This double aperture design helps to optimize imaging performance, especially when processing images under complex lighting conditions.

[0040] The system parameters of the lens are shown in Table 1, and the surface parameters are shown in Table 2.

[0041] Table 1. System parameters

[0042] EFL 11.11 BFL 1.61 F / # 2 FOV ±15°

[0043] Table 2. Surface parameters

[0044] Surf Type Radius Thickness Nd Vd Physical surface STANDARD Infinity 1000 S1 STANDARD 8.710 9.902 1.713 53.833 S2 STANDARD -23.470 0.503 S3 STANDARD -11.630 1.797 1.740 28.292 S4 STANDARD 51.199 1.226 S5(STO) STANDARD Infinity 1.960 S6 STANDARD 30.704 1.448 1.665 54.658 S7 STANDARD -12.121 0.767 S8 STANDARD 11.692 2.000 1.697 55.526 S9 STANDARD 60.866 1.557 S10 STANDARD -5.987 2.033 1.74 28.292 S11 STANDARD 39.185 1.613 S12(IMA) STANDARD Infinity

[0045] The above S1~S12 are respectively Figure 1 The surfaces of each lens, the system aperture S5 and the imaging surface S12 correspond.

[0046] According to the system parameters in Table 1, we can know:

[0047] EFL (effective focal length): 11.11mm;

[0048] BFL (back focal length): 1.61mm;

[0049] F / # (aperture number): 2.0, indicating that this is a large aperture lens capable of capturing brighter images in low-light conditions.

[0050] FOV (Field of View): ±15°, which means that the lens can cover a wider viewing angle range and is suitable for a variety of application scenarios.

[0051] Table 2 lists the type, radius, thickness, and corresponding refractive index (Nd) and Abbe number (Vd) of each surface, as follows:

[0052] The first lens 1 is made of crown glass, which has a refractive index of 1.713 and an Abbe number of 53.833, which helps to reduce dispersion and improve transmittance.

[0053] The second lens 2 is made of heavy flint glass with a refractive index greater than 1.7 and an Abbe number greater than 20 to increase dispersion to better correct chromatic aberration.

[0054] The third lens 3 is also made of crown glass with a refractive index between 1.2 and 1.7 and an Abbe number greater than 40, which further optimizes chromatic aberration correction.

[0055] The fourth lens 4 is also made of crown glass, with a refractive index between 1.5 and 1.7 and an Abbe number between 40 and 60, which helps to adjust the overall length of the system and maintain excellent imaging quality.

[0056] The fifth lens 5 again uses heavy flint glass with a refractive index between 1.6 and 1.8 and an Abbe number between 20 and 40, and is mainly used to correct chromatic aberration and other types of aberrations.

[0057] In one embodiment, the first lens 1 comprises a convex lens with positive power, the material of the first lens 1 is crown glass, the refractive index of the first lens 1 is between 1.6 and 1.8, and the Abbe number of the first lens 1 is between 40 and 60.

[0058] In this embodiment, the first lens 1 includes a convex lens with positive power, and the material thereof is crown glass. Crown glass is selected because it has good transmittance and small dispersion characteristics in the visible light band, which helps to reduce chromatic aberration. The refractive index of the first lens 1 is set between 1.6 and 1.8, and the Abbe number is in the range of 40 to 60. Such a combination can effectively control spherical aberration and provide sufficient correction ability to balance other types of aberrations, such as coma and distortion.

[0059] In one embodiment, the second lens 2 includes a concave lens with negative optical power, the material of the second lens 2 is heavy flint glass, the refractive index of the second lens 2 is greater than 1.7, and the Abbe number of the second lens 2 is greater than 20.

[0060] In this embodiment, the second lens 2 is a concave lens with negative power, and is made of heavy flint glass, whose refractive index is greater than 1.7 and whose Abbe number is greater than 20. The heavy flint glass is selected to increase the dispersion of the system by utilizing its higher refractive index and relatively low Abbe number, thereby enhancing the separation effect of light of different colors, thereby better correcting chromatic aberration.

[0061] In one embodiment, the third lens 3 comprises a convex lens with positive power. The material of the third lens 3 is crown glass. The refractive index of the third lens 3 is between 1.2 and 1.7. The Abbe number of the third lens 3 is greater than 40.

[0062] In this embodiment, the third lens 3 is designed to further optimize the aberration correction in the system, especially chromatic aberration, while maintaining good imaging quality.

[0063] In one embodiment, the fourth lens 4 comprises a convex lens with positive power, the material of the fourth lens 4 is crown glass, the refractive index of the fourth lens 4 is between 1.5 and 1.7, and the Abbe number of the fourth lens 4 is between 40 and 60.

[0064] In this embodiment, the main function of the fourth lens 4 is to help adjust the total length of the system without sacrificing the optical performance, and to work together with the first three lenses to ensure the imaging quality of the entire system.

[0065] In one embodiment, the fifth lens 5 includes a concave lens with negative optical power, the material of the fifth lens 5 is heavy flint glass, the refractive index of the fifth lens 5 is between 1.6 and 1.8, and the Abbe number of the fifth lens 5 is between 20 and 40.

[0066] In this embodiment, the fifth lens 5 is used for final aberration correction, especially chromatic aberration and field curvature, and for controlling the angle of light emitted from the lens to make it suitable for projection applications.

[0067] In one embodiment, the optical interval between the first lens 1 and the second lens 2 is 0.5 mm, and the optical interval between the second lens 2 and the third lens 3 is 3.1 mm.

[0068] In one embodiment, the optical interval between the third lens 3 and the fourth lens 4 is 0.8 mm, and the optical interval between the fourth lens 4 and the fifth lens 5 is 1.6 mm.

[0069] In one embodiment, the optical distance between the fifth lens element 5 and the image plane is 1.6 mm.

[0070] The above optical spacing is intended to ensure optimal imaging performance and compact structural size.

[0071] In this embodiment, through the above-mentioned architecture and material combination, this embodiment achieves a large aperture of F number 2, which means that a brighter image can be obtained under low light conditions. In addition, the full field of view> ±15° and MTF> 0.3@128lp / mm indicate that the system can provide high resolution and contrast over a wide viewing angle, which is critical for vehicle light projection lenses. The ratio of back focus to focal length BFL / EFL<0.3, and the ratio of total length to focal length TTL / EFL<0.7, these two parameters reflect that the system can effectively shorten the overall length, making the design lighter, which is not only conducive to saving space, but also reducing weight, which is particularly important for vehicle-mounted equipment.

[0072] The present embodiment adopts a structure composed of 5 spherical glass lenses, which not only ensures a high MTF value (>0.3@128lp / mm), but also provides excellent resolution and contrast in the entire field of view, and can maintain good imaging effects even in a large field of view of ±15°. The distortion in the entire field of view is controlled within 1%, thanks to the carefully designed optical path and reasonable material selection, which makes the imaging distortion extremely small and suitable for precision measurement and detection tasks. The red-green and blue-green differences are all controlled within 2μm, indicating that this lens has excellent color reproduction capabilities, which is particularly important for applications that require accurate color information. The length of the entire optical system is only about 11mm, which not only reduces space occupancy, but also reduces manufacturing costs, and is also easy to integrate into various devices. Although there is no special emphasis on temperature characteristics, the selected materials and structural design ensure stable performance at different ambient temperatures and adapt to relatively harsh working conditions.

[0073] See also Figures 2 to 8 ,from Figure 4 As can be seen from the field curvature and distortion diagram, the lens keeps distortion at an extremely low level (less than 1%) over the entire field of view. This means that the lens can provide an imaging effect that is very close to the real ratio, and is particularly suitable for distortion-sensitive applications such as precision measurement or high-quality photography.

[0074] pass Figure 3 From the ray fan diagram, it can be observed that aberrations such as spherical aberration and chromatic aberration are effectively suppressed throughout the field of view. This shows that advanced optical correction technology is used in the lens design to ensure that high clarity and color accuracy are maintained even at the edge of the image.

[0075] in accordance with Figure 5 As shown in the figure, both the red-green and blue-green color differences are controlled within 2 microns. This level of chromatic aberration control means that even in complex lighting conditions, the lens can reduce color fringing and improve the overall image quality.

[0076] from Figure 6 , Figure 7 and Figure 8 The light transfer function diagrams at different temperatures (25°C, 85°C and 105°C) show that the lens can maintain stable optical performance over a wide operating temperature range. This is especially important for equipment that needs to work in extreme environments, such as outdoor monitoring systems or industrial detection devices.

[0077] In summary, the lens in this embodiment has excellent distortion control capability, outstanding aberration correction effect, fine chromatic aberration management, and good environmental adaptability. These characteristics make the lens very suitable for use in professional fields with strict requirements on image quality and stability.

[0078] The above-mentioned large aperture industrial vision inspection lens applied to the self-closing loop of car lights, by designing a large aperture combination in the lens system, adopting the first, third and fourth lenses 4 as positive focal length lenses, and the second and fifth lenses 5 as negative focal length lenses, can realize effective collection and focusing of light, thereby increasing the aperture size; the configuration of positive and negative focal length lenses optimizes the propagation path of light, so that the system can reduce the size of the optical structure while ensuring the optical performance, thereby achieving a compact design; reasonable lens material and optical spacing design enable the lens to maintain stable optical performance at different ambient temperatures; ultimately achieving higher light collection capability, smaller lens size and good temperature adaptability.

[0079] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A large aperture industrial visual inspection lens for a self-closing loop of a vehicle lamp, characterized in that: include: A first lens, a second lens, a third lens, a fourth lens, and a fifth lens are arranged in sequence from the object side to the image side along the optical axis; wherein the first lens, the third lens, and the fourth lens have positive optical power respectively; and the second lens and the fifth lens have negative optical power respectively.

2. According to claim 1, a large aperture industrial visual inspection lens applied to a self-closing loop of a vehicle lamp is characterized in that: A system stop is arranged between the second lens and the third lens; and a vignetting stop is arranged on a surface of the second lens close to the first lens.

3. The large aperture industrial visual inspection lens for a self-closing loop of a vehicle lamp according to claim 1, characterized in that: The first lens includes a convex lens with positive power. The material of the first lens is crown glass. The refractive index of the first lens is between 1.6 and 1.

8. The Abbe number of the first lens is between 40 and 60.

4. The large aperture industrial visual inspection lens for a self-closing loop of a vehicle lamp according to claim 1, characterized in that: The second lens comprises a concave lens with negative optical power. The material of the second lens is heavy flint glass. The refractive index of the second lens is greater than 1.

7. The Abbe number of the second lens is greater than 20.

5. The large aperture industrial visual inspection lens for a self-closing loop of a vehicle lamp according to claim 1, characterized in that: The third lens comprises a convex lens with positive power. The material of the third lens is crown glass. The refractive index of the third lens is between 1.2 and 1.

7. The Abbe number of the third lens is greater than 40.

6. The large aperture industrial visual inspection lens for a self-closing loop of a vehicle lamp according to claim 1, characterized in that: The fourth lens comprises a convex lens with positive power. The material of the fourth lens is crown glass. The refractive index of the fourth lens is between 1.5 and 1.

7. The Abbe number of the fourth lens is between 40 and 60.

7. The large aperture industrial visual inspection lens for a self-closing loop of a vehicle lamp according to claim 1, characterized in that: The fifth lens comprises a concave lens with negative optical power. The material of the fifth lens is heavy flint glass. The refractive index of the fifth lens is between 1.6 and 1.

8. The Abbe number of the fifth lens is between 20 and 40.

8. The large aperture industrial visual inspection lens for a self-closing loop of a vehicle lamp according to claim 1, characterized in that: The optical interval between the first lens and the second lens is 0.5 mm, and the optical interval between the second lens and the third lens is 3.1 mm.

9. The large aperture industrial visual inspection lens for a self-closing loop of a vehicle lamp according to claim 1, characterized in that: An optical interval between the third lens and the fourth lens is 0.8 mm, and an optical interval between the fourth lens and the fifth lens is 1.6 mm.

10. The large aperture industrial visual inspection lens for a self-closing loop of a vehicle lamp according to claim 1, characterized in that: An optical distance between the fifth lens and the image plane is 1.6 mm.

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